Interaction between bacteria and cholesterol crystals: Implications for endocarditis and atherosclerosis.

Area of Science:

• Microbiology
• Cardiovascular Research
• Pathogenesis

Background:

• Cholesterol crystals (CCs) are prevalent in atherosclerotic plaques and sclerotic cardiac valves.
• The interaction between pathogenic bacteria and CCs remains unexplored.
• Understanding this interaction may illuminate plaque destabilization and bacterial adherence to valves.

Purpose of the Study:

• To investigate the interaction between pathogenic bacteria and cholesterol crystals (CCs).
• To assess bacterial adhesion to and proliferation on CCs.
• To evaluate the role of CCs in bacterial colonization of atherosclerotic lesions and cardiac valves.

Main Methods:

• In vitro assessment of Staphylococcus aureus and Pseudomonas aeruginosa adhesion and growth on CCs versus control surfaces.
• Ex vivo evaluation of bacterial burden in atherosclerotic arteries and human carotid plaques.
• Scanning electron microscopy (SEM) and confocal microscopy to visualize bacterial-CC interactions and cholesterol binding.

Main Results:

• S. aureus and P. aeruginosa showed significantly increased adhesion and growth on CCs compared to controls.
• Atherosclerotic arteries and human plaques exhibited higher bacterial loads.
• SEM confirmed bacterial adhesion to and degradation of CCs, with increased cholesterol binding to bacteria.

Conclusions:

• This is the first study demonstrating that bacteria dissolve and bind to CCs.
• This interaction provides a mechanism for bacterial adhesion to sclerotic valves and atherosclerotic plaques.
• The findings may contribute to understanding endocarditis and plaque destabilization.